Previously the statistics collector received statistics updates via UDP and
shared statistics data by writing them out to temporary files regularly. These
files can reach tens of megabytes and are written out up to twice a
second. This has repeatedly prevented us from adding additional useful
statistics.
Now statistics are stored in shared memory. Statistics for variable-numbered
objects are stored in a dshash hashtable (backed by dynamic shared
memory). Fixed-numbered stats are stored in plain shared memory.
The header for pgstat.c contains an overview of the architecture.
The stats collector is not needed anymore, remove it.
By utilizing the transactional statistics drop infrastructure introduced in a
prior commit statistics entries cannot "leak" anymore. Previously leaked
statistics were dropped by pgstat_vacuum_stat(), called from [auto-]vacuum. On
systems with many small relations pgstat_vacuum_stat() could be quite
expensive.
Now that replicas drop statistics entries for dropped objects, it is not
necessary anymore to reset stats when starting from a cleanly shut down
replica.
Subsequent commits will perform some further code cleanup, adapt docs and add
tests.
Bumps PGSTAT_FILE_FORMAT_ID.
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-By: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-By: Tomas Vondra <tomas.vondra@2ndquadrant.com> (in a much earlier version)
Reviewed-By: Arthur Zakirov <a.zakirov@postgrespro.ru> (in a much earlier version)
Reviewed-By: Antonin Houska <ah@cybertec.at> (in a much earlier version)
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Discussion: https://postgr.es/m/20220308205351.2xcn6k4x5yivcxyd@alap3.anarazel.de
Discussion: https://postgr.es/m/20210319235115.y3wz7hpnnrshdyv6@alap3.anarazel.de
The column 'subskiplsn' uses TYPALIGN_DOUBLE (which has 4 bytes alignment
on AIX) for storage. But the C Struct (Form_pg_subscription) has 8-byte
alignment for this field, so retrieving it from storage causes an
unaligned read.
To fix this, we rearranged the 'subskiplsn' column in the catalog so that
it naturally comes at an 8-byte boundary.
We have fixed a similar problem in commit f3b421da5f. This patch adds a
test to avoid a similar mistake in the future.
Reported-by: Noah Misch
Diagnosed-by: Noah Misch, Masahiko Sawada, Amit Kapila
Author: Masahiko Sawada
Reviewed-by: Noah Misch, Amit Kapila
Discussion: https://postgr.es/m/20220401074423.GC3682158@rfd.leadboat.comhttps://postgr.es/m/CAD21AoDeScrsHhLyEPYqN3sydg6PxAPVBboK=30xJfUVihNZDA@mail.gmail.com
This option is useful to do a rewind with the server configuration file
(aka postgresql.conf) located outside the data directory, which is
something that some Linux distributions and some HA tools like to rely
on. As a result, this can simplify the logic around a rewind by
avoiding the copy of such files before running pg_rewind.
This option affects pg_rewind when it internally starts the target
cluster with some "postgres" commands, adding -c config_file=FILE to the
command strings generated, when:
- retrieving a restore_command using a "postgres -C" command for
-c/--restore-target-wal.
- forcing crash recovery once to get the cluster into a clean shutdown
state.
Author: Gunnar "Nick" Bluth
Reviewed-by: Michael Banck, Alexander Kukushkin, Michael Paquier,
Alexander Alekseev
Discussion: https://postgr.es/m/7c59265d-ac50-b0aa-ca1e-65e8bd27642a@pro-open.de
Exclusive-mode backups have been deprecated since 9.6 (when
non-exclusive backups were introduced) due to the issues
they can cause should the system crash while one is running and
generally because non-exclusive provides a much better interface.
Further, exclusive backup mode wasn't really being tested (nor was most
of the related code- like being able to log in just to stop an exclusive
backup and the bits of the state machine related to that) and having to
possibly deal with an exclusive backup and the backup_label file
existing during pg_basebackup, pg_rewind, etc, added other complexities
that we are better off without.
This patch removes the exclusive backup mode, the various special cases
for dealing with it, and greatly simplifies the online backup code and
documentation.
Authors: David Steele, Nathan Bossart
Reviewed-by: Chapman Flack
Discussion: https://postgr.es/m/ac7339ca-3718-3c93-929f-99e725d1172c@pgmasters.nethttps://postgr.es/m/CAHg+QDfiM+WU61tF6=nPZocMZvHDzCK47Kneyb0ZRULYzV5sKQ@mail.gmail.com
This patch allows "PGC_SUSET" parameters to be set by non-superusers
if they have been explicitly granted the privilege to do so.
The privilege to perform ALTER SYSTEM SET/RESET on a specific parameter
can also be granted.
Such privileges are cluster-wide, not per database. They are tracked
in a new shared catalog, pg_parameter_acl.
Granting and revoking these new privileges works as one would expect.
One caveat is that PGC_USERSET GUCs are unaffected by the SET privilege
--- one could wish that those were handled by a revocable grant to
PUBLIC, but they are not, because we couldn't make it robust enough
for GUCs defined by extensions.
Mark Dilger, reviewed at various times by Andrew Dunstan, Robert Haas,
Joshua Brindle, and myself
Discussion: https://postgr.es/m/3D691E20-C1D5-4B80-8BA5-6BEB63AF3029@enterprisedb.com
Commit 4a39f87acd changed the aggregated log format. Problem is, now
the explanatory paragraph for the log line in the document is too
long. Also the log format included more optional columns, and it's
harder to parse the log lines. This commit tries to solve the
problems.
- There's no optional log columns anymore. If a column is not
meaningful with provided pgbench option, it will be presented as 0.
- Reorder the log columns so that it's easier to parse them.
- Adjust explanatory paragraph for the log line in the doc.
Discussion: https://postgr.es/m/flat/202203280757.3tu4ovs3petm%40alvherre.pgsql
Previously, psql printed only the last result if a command string
returned multiple result sets. Now it prints all of them. The
previous behavior can be obtained by setting the psql variable
SHOW_ALL_RESULTS to off.
This is a significantly enhanced version of
3a51306722 (that was later reverted).
There is also much more test coverage for various psql features now.
Author: Fabien COELHO <coelho@cri.ensmp.fr>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: "Iwata, Aya" <iwata.aya@jp.fujitsu.com> (earlier version)
Reviewed-by: Daniel Verite <daniel@manitou-mail.org> (earlier version)
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> (earlier version)
Reviewed-by: vignesh C <vignesh21@gmail.com> (earlier version)
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre
When VACUUM set relfrozenxid before now, it set it to whatever value was
used to determine which tuples to freeze -- the FreezeLimit cutoff.
This approach was very naive. The relfrozenxid invariant only requires
that new relfrozenxid values be <= the oldest extant XID remaining in
the table (at the point that the VACUUM operation ends), which in
general might be much more recent than FreezeLimit.
VACUUM now carefully tracks the oldest remaining XID/MultiXactId as it
goes (the oldest remaining values _after_ lazy_scan_prune processing).
The final values are set as the table's new relfrozenxid and new
relminmxid in pg_class at the end of each VACUUM. The oldest XID might
come from a tuple's xmin, xmax, or xvac fields. It might even come from
one of the table's remaining MultiXacts.
Final relfrozenxid values must still be >= FreezeLimit in an aggressive
VACUUM (FreezeLimit still acts as a lower bound on the final value that
aggressive VACUUM can set relfrozenxid to). Since standard VACUUMs
still make no guarantees about advancing relfrozenxid, they might as
well set relfrozenxid to a value from well before FreezeLimit when the
opportunity presents itself. In general standard VACUUMs may now set
relfrozenxid to any value > the original relfrozenxid and <= OldestXmin.
Credit for the general idea of using the oldest extant XID to set
pg_class.relfrozenxid at the end of VACUUM goes to Andres Freund.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Andres Freund <andres@anarazel.de>
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CAH2-WzkymFbz6D_vL+jmqSn_5q1wsFvFrE+37yLgL_Rkfd6Gzg@mail.gmail.com
VACUUM VERBOSE and autovacuum log reports were taught to report the
details of how VACUUM advanced relfrozenxid (and relminmxid) by commit
872770fd. Highlight this by adding a "Tip" to the documentation, next
to related discussion of age(relfrozenxid) monitoring.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-Wzk0C1O-MKkOrj4YAfsGRru2=cA2VQpqM-9R1HNuG3nFaQ@mail.gmail.com
Adjust the documentation's coverage of aggressive VACUUMs to make it
clearer that aggressive vacuuming isn't always strictly necessary. It's
possible for non-aggressive VACUUMs to advance relfrozenxid/relminmxid
without fail, given the right workload conditions.
While this has always been true, it matters more with recent and pending
improvements to VACUUM. These improvements make non-aggressive
vacuuming more likely to advance relfrozenxid/relminmxid in practice.
While this is an unrelated improvement to the docs, formally speaking,
it still doesn't seem worth backpatching. So don't backpatch.
This is essentially the same as applying VACUUM FULL to a partitioned
table, which has been supported since commit 3c3bb99330 (March 2017).
While there's no great use case in applying CLUSTER to partitioned
tables, we don't have any strong reason not to allow it either.
For now, partitioned indexes cannot be marked clustered, so an index
must always be specified.
While at it, rename some variables that were RangeVars during the
development that led to 8bc717cb88 but never made it that way to the
source tree; there's no need to perpetuate names that have always been
more confusing than helpful.
Author: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/20201028003312.GU9241@telsasoft.com
Discussion: https://postgr.es/m/20200611153502.GT14879@telsasoft.com
Remove circular "25.1.5.1. Multixacts And Wraparound" link that
references the section that the link itself appears in. An explanation
of MultiXactId age appears only a few sentences before the link, so
there's no question that the link is superfluous at best.
Oversight in commit d5409295.
Author: Peter Geoghegan <pg@bowt.ie>
Backpatch: 14-
322becb has changed upgradecheck to use the TAP tests, discarding
pg_upgrade's tests in bincheck. However, this is proving to be a bad
idea for the Windows buildfarm clients that use MSVC when TAP tests are
disabled as this causes a hard failure at the pg_upgrade step.
This commit disables upgradecheck, moving the execution of the tests of
pg_upgrade to bincheck, as per an initial suggestion from Andres
Freund, so as the buildfarm is able to live happily with those changes.
While on it, remove the routine that was used by upgradecheck to
create databases whose names are generated with a range of ASCII
characters as it is not used since 322becb. upgradecheck is removed
from the CI script for Windows, as bincheck takes care of that now.
Per report from buildfarm member hamerkop (MSVC 2017 without a TAP
setup).
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/YkbnpriYEAagZ2wH@paquier.xyz
It emerges that our new zstd code depends on features that were not
present (or at least not enabled by default) in zstd before 1.4.0.
That's already four years old, so there's little reason to try to
make our code work with something older. Instead make configure
check that zstd is at least 1.4.0, and document this requirement.
Justin Pryzby (doc changes by me)
Discussion: https://postgr.es/m/efbd94cd1102f99fd1300e44905ee4a994ee2ef6.camel@gunduz.org
The current implementation supports exactly one IP address in a server
certificate's Common Name, which is brittle (the strings must match
exactly). This patch adds support for IPv4 and IPv6 addresses in a
server's Subject Alternative Names.
Per discussion on-list:
- If the client's expected host is an IP address, we allow fallback to
the Subject Common Name if an iPAddress SAN is not present, even if
a dNSName is present. This matches the behavior of NSS, in
violation of the relevant RFCs.
- We also, counter-intuitively, match IP addresses embedded in dNSName
SANs. From inspection this appears to have been the behavior since
the SAN matching feature was introduced in acd08d76.
- Unlike NSS, we don't map IPv4 to IPv6 addresses, or vice-versa.
Author: Jacob Champion <pchampion@vmware.com>
Co-authored-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Co-authored-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/flat/9f5f20974cd3a4091a788cf7f00ab663d5fcdffe.camel@vmware.com
When we create or alter a subscription to add publications raise a warning
for non-existent publications. We don't want to give an error here because
it is possible that users can later create the missing publications.
Author: Vignesh C
Reviewed-by: Bharath Rupireddy, Japin Li, Dilip Kumar, Euler Taveira, Ashutosh Sharma, Amit Kapila
Discussion: https://postgr.es/m/CALDaNm0f4YujGW+q-Di0CbZpnQKFFrXntikaQQKuEmGG0=Zw=Q@mail.gmail.com
When evaluating a query with a multi-column GROUP BY clause using sort,
the cost may be heavily dependent on the order in which the keys are
compared when building the groups. Grouping does not imply any ordering,
so we're allowed to compare the keys in arbitrary order, and a Hash Agg
leverages this. But for Group Agg, we simply compared keys in the order
as specified in the query. This commit explores alternative ordering of
the keys, trying to find a cheaper one.
In principle, we might generate grouping paths for all permutations of
the keys, and leave the rest to the optimizer. But that might get very
expensive, so we try to pick only a couple interesting orderings based
on both local and global information.
When planning the grouping path, we explore statistics (number of
distinct values, cost of the comparison function) for the keys and
reorder them to minimize comparison costs. Intuitively, it may be better
to perform more expensive comparisons (for complex data types etc.)
last, because maybe the cheaper comparisons will be enough. Similarly,
the higher the cardinality of a key, the lower the probability we’ll
need to compare more keys. The patch generates and costs various
orderings, picking the cheapest ones.
The ordering of group keys may interact with other parts of the query,
some of which may not be known while planning the grouping. E.g. there
may be an explicit ORDER BY clause, or some other ordering-dependent
operation, higher up in the query, and using the same ordering may allow
using either incremental sort or even eliminate the sort entirely.
The patch generates orderings and picks those minimizing the comparison
cost (for various pathkeys), and then adds orderings that might be
useful for operations higher up in the plan (ORDER BY, etc.). Finally,
it always keeps the ordering specified in the query, on the assumption
the user might have additional insights.
This introduces a new GUC enable_group_by_reordering, so that the
optimization may be disabled if needed.
The original patch was proposed by Teodor Sigaev, and later improved and
reworked by Dmitry Dolgov. Reviews by a number of people, including me,
Andrey Lepikhov, Claudio Freire, Ibrar Ahmed and Zhihong Yu.
Author: Dmitry Dolgov, Teodor Sigaev, Tomas Vondra
Reviewed-by: Tomas Vondra, Andrey Lepikhov, Claudio Freire, Ibrar Ahmed, Zhihong Yu
Discussion: https://postgr.es/m/7c79e6a5-8597-74e8-0671-1c39d124c9d6%40sigaev.ru
Discussion: https://postgr.es/m/CA%2Bq6zcW_4o2NC0zutLkOJPsFt80megSpX_dVRo6GK9PC-Jx_Ag%40mail.gmail.com
This Patch introduces three SQL standard JSON functions:
JSON() (incorrectly mentioned in my commit message for f4fb45d15c)
JSON_SCALAR()
JSON_SERIALIZE()
JSON() produces json values from text, bytea, json or jsonb values, and
has facilitites for handling duplicate keys.
JSON_SCALAR() produces a json value from any scalar sql value, including
json and jsonb.
JSON_SERIALIZE() produces text or bytea from input which containis or
represents json or jsonb;
For the most part these functions don't add any significant new
capabilities, but they will be of use to users wanting standard
compliant JSON handling.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
libzstd allows transparent parallel compression just by setting
an option when creating the compression context, so permit that
for both client and server-side backup compression. To use this,
use something like pg_basebackup --compress WHERE-zstd:workers=N
where WHERE is "client" or "server" and N is an integer.
When compression is performed on the server side, this will spawn
threads inside the PostgreSQL backend. While there is almost no
PostgreSQL server code which is thread-safe, the threads here are used
internally by libzstd and touch only data structures controlled by
libzstd.
Patch by me, based in part on earlier work by Dipesh Pandit
and Jeevan Ladhe. Reviewed by Justin Pryzby.
Discussion: http://postgr.es/m/CA+Tgmobj6u-nWF-j=FemygUhobhryLxf9h-wJN7W-2rSsseHNA@mail.gmail.com
SSL has become the de facto term to mean an end-to-end encrypted channel
regardless of protocol used, even though the SSL protocol is deprecated.
Clarify what we mean with SSL in our documentation, especially for new
users who might be looking for TLS.
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/D4ABB281-6CFD-46C6-A4E0-8EC23A2977BC@yesql.se
COPY FROM supports the HEADER option to silently discard the header
line from a CSV or text file. It is possible to load by mistake a
file that matches the expected format, for example, if two text
columns have been swapped, resulting in garbage in the database.
This adds a new option value HEADER MATCH that checks the column names
in the header line against the actual column names and errors out if
they do not match.
Author: Rémi Lapeyre <remi.lapeyre@lenstra.fr>
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAF1-J-0PtCWMeLtswwGV2M70U26n4g33gpe1rcKQqe6wVQDrFA@mail.gmail.com
Because this strategy logs changes on a block-by-block basis, it
avoids the need to checkpoint before and after the operation.
However, because it logs each changed block individually, it might
generate a lot of extra write-ahead logging if the template database
is large. Therefore, the older strategy remains available via a new
STRATEGY parameter to CREATE DATABASE, and a corresponding --strategy
option to createdb.
Somewhat controversially, this patch assembles the list of relations
to be copied to the new database by reading the pg_class relation of
the template database. Cross-database access like this isn't normally
possible, but it can be made to work here because there can't be any
connections to the database being copied, nor can it contain any
in-doubt transactions. Even so, we have to use lower-level interfaces
than normal, since the table scan and relcache interfaces will not
work for a database to which we're not connected. The advantage of
this approach is that we do not need to rely on the filesystem to
determine what ought to be copied, but instead on PostgreSQL's own
knowledge of the database structure. This avoids, for example,
copying stray files that happen to be located in the source database
directory.
Dilip Kumar, with a fairly large number of cosmetic changes by me.
Reviewed and tested by Ashutosh Sharma, Andres Freund, John Naylor,
Greg Nancarrow, Neha Sharma. Additional feedback from Bruce Momjian,
Heikki Linnakangas, Julien Rouhaud, Adam Brusselback, Kyotaro
Horiguchi, Tomas Vondra, Andrew Dunstan, Álvaro Herrera, and others.
Discussion: http://postgr.es/m/CA+TgmoYtcdxBjLh31DLxUXHxFVMPGzrU5_T=CYCvRyFHywSBUQ@mail.gmail.com
The original first half of the example used an employees table and an
accounts.sales_person foreign key column, while the second half (added
in commit 8f889b1083) used a salesmen table and accounts.sales_id
for the foreign key. This makes everything use the original names.
Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://postgr.es/m/87o81vqjw0.fsf@wibble.ilmari.org
Currently, libpq client code must have a connection handle
before it can query the "library" SSL attribute. This poses
problems if the client needs to know what SSL library is in
use before constructing a connection string.
Allow PQsslAttribute(NULL, "library") to return the library
in use -- currently, just "OpenSSL" or NULL. The new behavior
is announced with the LIBPQ_HAS_SSL_LIBRARY_DETECTION feature
macro, allowing clients to differentiate between a libpq that
was compiled without SSL support and a libpq that's just too
old to tell.
Author: Jacob Champion <pchampion@vmware.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/4c8b76ef434a96627170a31c3acd33cbfd6e41f1.camel@vmware.com
This view is similar to pg_hba_file_rules view, except that it is
associated with the parsing of pg_ident.conf. Similarly to its cousin,
this view is useful to check via SQL if changes planned in pg_ident.conf
would work upon reload or restart, or to diagnose a previous failure.
Bumps catalog version.
Author: Julien Rouhaud
Reviewed-by: Aleksander Alekseev, Michael Paquier
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
Generally if a role is granted membership to another role with NOINHERIT
they must use SET ROLE to access the privileges of that role, however
with predefined roles the membership and privilege is conflated. Fix that
by replacing is_member_of_role with has_privs_for_role for predefined
roles. Patch does not remove is_member_of_role from acl.h, but it does
add a warning not to use that function for privilege checking. Not
backpatched based on hackers list discussion.
Author: Joshua Brindle
Reviewed-by: Stephen Frost, Nathan Bossart, Joe Conway
Discussion: https://postgr.es/m/flat/CAGB+Vh4Zv_TvKt2tv3QNS6tUM_F_9icmuj0zjywwcgVi4PAhFA@mail.gmail.com
Commit f9fd176461 effectively gave
every role ADMIN OPTION on itself. However, this appears to be
something that happened accidentally as a result of refactoring
work rather than an intentional decision. Almost a decade later,
it was discovered that this was a security vulnerability. As a
result, commit fea164a72a restricted
this implicit ADMIN OPTION privilege to be exercisable only when
the role being administered is the same as the session user and
when no security-restricted operation is in progress. That
commit also documented the existence of this implicit privilege
for what seems to be the first time.
The effect of the privilege is to allow a login role to grant
the privileges of that role, and optionally ADMIN OPTION on it,
to some other role. That's an unusual thing to do, because generally
membership is granted in roles used as groups, rather than roles
used as users. Therefore, it does not seem likely that removing
the privilege will break things for many PostgreSQL users.
However, it will make it easier to reason about the permissions
system. This is the only case where a user who has not been given any
special permission (superuser, or ADMIN OPTION on some role) can
modify role membership, so removing it makes things more consistent.
For example, if a superuser sets up role A and B and grants A to B
but no other privileges to anyone, she can now be sure that no one
else will be able to revoke that grant. Without this change, that
would have been true only if A was a non-login role.
Patch by me. Reviewed by Tom Lane and Stephen Frost.
Discussion: http://postgr.es/m/CA+Tgmoawdt03kbA+dNyBcNWJpRxu0f4X=69Y3+DkXXZqmwMDLg@mail.gmail.com
MERGE performs actions that modify rows in the target table using a
source table or query. MERGE provides a single SQL statement that can
conditionally INSERT/UPDATE/DELETE rows -- a task that would otherwise
require multiple PL statements. For example,
MERGE INTO target AS t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
DELETE
WHEN NOT MATCHED AND s.delta > 0 THEN
INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED THEN
DO NOTHING;
MERGE works with regular tables, partitioned tables and inheritance
hierarchies, including column and row security enforcement, as well as
support for row and statement triggers and transition tables therein.
MERGE is optimized for OLTP and is parameterizable, though also useful
for large scale ETL/ELT. MERGE is not intended to be used in preference
to existing single SQL commands for INSERT, UPDATE or DELETE since there
is some overhead. MERGE can be used from PL/pgSQL.
MERGE does not support targetting updatable views or foreign tables, and
RETURNING clauses are not allowed either. These limitations are likely
fixable with sufficient effort. Rewrite rules are also not supported,
but it's not clear that we'd want to support them.
Author: Pavan Deolasee <pavan.deolasee@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Simon Riggs <simon.riggs@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier versions)
Reviewed-by: Peter Geoghegan <pg@bowt.ie> (earlier versions)
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions)
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.com
Discussion: https://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com
Discussion: https://postgr.es/m/20201231134736.GA25392@alvherre.pgsql
When dealing with partitioned tables, counters for partitioned tables
are not updated when modifying child tables. This means autoanalyze may
not update optimizer statistics for the parent relations, which can
result in poor plans for some queries.
It's worth documenting this limitation, so that people are aware of it
and can take steps to mitigate it (e.g. by setting up a script executing
ANALYZE regularly).
Backpatch to v10. Older branches are affected too, of couse, but we no
longer maintain those.
Author: Justin Pryzby
Reviewed-by: Zhihong Yu, Tomas Vondra
Backpatch-through: 10
Discussion: https://postgr.es/m/20210913035409.GA10647%40telsasoft.com
This allows specifying an optional column list when adding a table to
logical replication. The column list may be specified after the table
name, enclosed in parentheses. Columns not included in this list are not
sent to the subscriber, allowing the schema on the subscriber to be a
subset of the publisher schema.
For UPDATE/DELETE publications, the column list needs to cover all
REPLICA IDENTITY columns. For INSERT publications, the column list is
arbitrary and may omit some REPLICA IDENTITY columns. Furthermore, if
the table uses REPLICA IDENTITY FULL, column list is not allowed.
The column list can contain only simple column references. Complex
expressions, function calls etc. are not allowed. This restriction could
be relaxed in the future.
During the initial table synchronization, only columns included in the
column list are copied to the subscriber. If the subscription has
several publications, containing the same table with different column
lists, columns specified in any of the lists will be copied.
This means all columns are replicated if the table has no column list
at all (which is treated as column list with all columns), or when of
the publications is defined as FOR ALL TABLES (possibly IN SCHEMA that
matches the schema of the table).
For partitioned tables, publish_via_partition_root determines whether
the column list for the root or the leaf relation will be used. If the
parameter is 'false' (the default), the list defined for the leaf
relation is used. Otherwise, the column list for the root partition
will be used.
Psql commands \dRp+ and \d <table-name> now display any column lists.
Author: Tomas Vondra, Alvaro Herrera, Rahila Syed
Reviewed-by: Peter Eisentraut, Alvaro Herrera, Vignesh C, Ibrar Ahmed,
Amit Kapila, Hou zj, Peter Smith, Wang wei, Tang, Shi yu
Discussion: https://postgr.es/m/CAH2L28vddB_NFdRVpuyRBJEBWjz4BSyTB=_ektNRH8NJ1jf95g@mail.gmail.com
Follow-up improvements for commit 127aea2a based on discussion:
* use fork name for --fork, not number
* use -R, -B as short switches for --relation, --block
* re-alphabetize the list of switches (code, --help and docs)
Suggested-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com> (fork name part)
Reviewed-by: David Christensen <david.christensen@crunchydata.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Discussion: https://postgr.es/m/3a4c2e93-7976-2320-fc0a-32097fe148a7%40enterprisedb.com
This commit adds support for decoding of sequences to the built-in
replication (the infrastructure was added by commit 0da92dc530).
The syntax and behavior mostly mimics handling of tables, i.e. a
publication may be defined as FOR ALL SEQUENCES (replicating all
sequences in a database), FOR ALL SEQUENCES IN SCHEMA (replicating
all sequences in a particular schema) or individual sequences.
To publish sequence modifications, the publication has to include
'sequence' action. The protocol is extended with a new message,
describing sequence increments.
A new system view pg_publication_sequences lists all the sequences
added to a publication, both directly and indirectly. Various psql
commands (\d and \dRp) are improved to also display publications
including a given sequence, or sequences included in a publication.
Author: Tomas Vondra, Cary Huang
Reviewed-by: Peter Eisentraut, Amit Kapila, Hannu Krosing, Andres
Freund, Petr Jelinek
Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com
Discussion: https://postgr.es/m/1710ed7e13b.cd7177461430746.3372264562543607781@highgo.ca
Up to now, the planner estimated the size of a recursive query's
worktable as 10 times the size of the non-recursive term. It's hard
to see how to do significantly better than that automatically, but
we can give users control over the multiplier to allow tuning for
specific use-cases. The default behavior remains the same.
Simon Riggs
Discussion: https://postgr.es/m/CANbhV-EuaLm4H3g0+BSTYHEGxJj3Kht0R+rJ8vT57Dejnh=_nA@mail.gmail.com
The command used in the documentation to retrieve the value of the
runtime-computed GUC shared_memory_size_in_huge_pages would also show to
the user all the log messages generated by the postmaster before and
after printing the wanted value. This can be confusing, as the wanted
result could be masked with a lot of noise.
One way to avoid those log messages is to use something like "-c
log_min_messages=fatal" in the command (my idea, but that's not common
knowledge). Rather than mentioning this option, suffix the command with
a redirection of stderr to /dev/null, which is the stream location where
the logs show up. This is enough to show only the GUC value to the
user when copy-pasting the command.
Reported-by: Magnus Hagander
Author: Nathan Bossart
Discussion: https://postgr.es/m/20220314173417.GA1020555@nathanxps13
There are more compression parameters that can be specified than just
an integer compression level, so rename the new COMPRESSION_LEVEL
option to COMPRESSION_DETAIL before it gets released. Introduce a
flexible syntax for that option to allow arbitrary options to be
specified without needing to adjust the main replication grammar,
and common code to parse it that is shared between the client and
the server.
This commit doesn't actually add any new compression parameters,
so the only user-visible change is that you can now type something
like pg_basebackup --compress gzip:level=5 instead of writing just
pg_basebackup --compress gzip:5. However, it should make it easy to
add new options. If for example gzip starts offering fries, we can
support pg_basebackup --compress gzip:level=5,fries=true for the
benefit of users who want fries with that.
Along the way, this fixes a few things in pg_basebackup so that the
pg_basebackup can be used with a server-side compression algorithm
that pg_basebackup itself does not understand. For example,
pg_basebackup --compress server-lz4 could still succeed even if
only the server and not the client has LZ4 support, provided that
the other options to pg_basebackup don't require the client to
decompress the archive.
Patch by me. Reviewed by Justin Pryzby and Dagfinn Ilmari Mannsåker.
Discussion: http://postgr.es/m/CA+TgmoYvpetyRAbbg1M8b3-iHsaN4nsgmWPjOENu5-doHuJ7fA@mail.gmail.com
When serialization or deadlock errors are reported by backend, allow
to retry and continue the benchmarking. For this purpose new options
"--max-tries", "--failures-detailed" and "--verbose-errors" are added.
Transactions with serialization errors or deadlock errors will be
repeated after rollbacks until they complete successfully or reach the
maximum number of tries (specified by the --max-tries option), or the
maximum time of tries (specified by the --latency-limit option).
These options can be specified at the same time. It is not possible to
use an unlimited number of tries (--max-tries=0) without the
--latency-limit option or the --time option. By default the option
--max-tries is set to 1, which means transactions with
serialization/deadlock errors are not retried. If the last try fails,
this transaction will be reported as failed, and the client variables
will be set as they were before the first run of this transaction.
Statistics on retries and failures are printed in the progress,
transaction / aggregation logs and in the end with other results (all
and for each script). Also retries and failures are printed
per-command with average latency by using option
(--report-per-command, -r).
Option --failures-detailed prints group failures by basic types
(serialization failures / deadlock failures).
Option --verbose-errors prints distinct reports on errors and failures
(errors without retrying) by type with detailed information like which
limit for retries was violated and how far it was exceeded for the
serialization/deadlock failures.
Patch originally written by Marina Polyakova then Yugo Nagata
inherited the discussion and heavily modified the patch to make it
commitable.
Authors: Yugo Nagata, Marina Polyakova
Reviewed-by: Fabien Coelho, Tatsuo Ishii, Alvaro Herrera, Kevin Grittner, Andres Freund, Arthur Zakirov, Alexander Korotkov, Teodor Sigaev, Ildus Kurbangaliev
Discussion: https://postgr.es/m/flat/72a0d590d6ba06f242d75c2e641820ec%40postgrespro.ru
A security invoker view checks permissions for accessing its
underlying base relations using the privileges of the user of the
view, rather than the privileges of the view owner. Additionally, if
any of the base relations are tables with RLS enabled, the policies of
the user of the view are applied, rather than those of the view owner.
This allows views to be defined without giving away additional
privileges on the underlying base relations, and matches a similar
feature available in other database systems.
It also allows views to operate more naturally with RLS, without
affecting the assignments of policies to users.
Christoph Heiss, with some additional hacking by me. Reviewed by
Laurenz Albe and Wolfgang Walther.
Discussion: https://postgr.es/m/b66dd6d6-ad3e-c6f2-8b90-47be773da240%40cybertec.at
This feature allows skipping the transaction on subscriber nodes.
If incoming change violates any constraint, logical replication stops
until it's resolved. Currently, users need to either manually resolve the
conflict by updating a subscriber-side database or by using function
pg_replication_origin_advance() to skip the conflicting transaction. This
commit introduces a simpler way to skip the conflicting transactions.
The user can specify LSN by ALTER SUBSCRIPTION ... SKIP (lsn = XXX),
which allows the apply worker to skip the transaction finished at
specified LSN. The apply worker skips all data modification changes within
the transaction.
Author: Masahiko Sawada
Reviewed-by: Takamichi Osumi, Hou Zhijie, Peter Eisentraut, Amit Kapila, Shi Yu, Vignesh C, Greg Nancarrow, Haiying Tang, Euler Taveira
Discussion: https://postgr.es/m/CAD21AoDeScrsHhLyEPYqN3sydg6PxAPVBboK=30xJfUVihNZDA@mail.gmail.com
Andres Freund